Image reading device

Abstract

An image reading device includes an angle restriction part 212 a that restricts an inclination angle with respect to a document table glass ( 203 ) when viewed from a sub-scanning direction of a flat cable ( 214 ) such that a contact portion is biased to one side of the flat cable ( 214 ) in a main scanning direction when an upper surface part of the flat cable ( 214 ) contacts with the document table glass ( 203 ) with movement of an image reading unit ( 210 ).

The invention claimed is: 
     
       1. An image reading device comprising:
 a housing mounted at an upper surface thereof with a document table glass; 
 an image reading unit that emits light toward the document table glass while reciprocally moving in a sub-scanning direction perpendicular to a main scanning direction between a bottom wall part of the housing and the document table glass; and 
 a flat cable having one end part connected to the image reading unit, the other end part fixed to the bottom wall part of the housing and arranged in an U shape consisting of an upper sidewall part, a lower sidewall part and a curved part for connecting the both sidewall parts when viewed from the main scanning direction, 
 wherein the image reading device further comprises: 
 an angle restriction part that restricts an inclination angle of the flat cable with respect to the document table glass when viewed from the sub-scanning direction of the flat cable such that when a contact portion between an upper surface part of the flat cable and the document table glass is generated with movement of the image reading unit, the contact portion is biased to one side of the flat cable in the main scanning direction. 
 
     
     
       2. The image reading device of  claim 1 , wherein the angle restriction part includes an inclination surface formed in the image reading unit and facing an upper surface of the upper sidewall part of the flat cable, and
 the inclination surface is upwardly inclined toward the one side from the other side in the main scanning direction. 
 
     
     
       3. The image reading device of  claim 1 , wherein the angle restriction part includes a slit-like insertion hole formed in the image reading unit and into which the upper sidewall part of the flat cable is inserted, and
 the insertion hole is upwardly inclined toward the one side from the other side in the main scanning direction. 
 
     
     
       4. The image reading device of  claim 1 , wherein the angle restriction part includes a wall part fixed to the image reading unit and facing the upper surface of the upper sidewall part of the flat cable, and
 the wall part is upwardly inclined toward the one side from the other side in the main scanning direction. 
 
     
     
       5. The image reading device of  claim 1 , wherein the image reading unit is provided with a connecting connector to which the one end part of the flat cable is connected,
 the connecting connector is upwardly inclined from the one side toward the other side in the main scanning direction, and 
 the angle restriction part is configured by the connecting connector. 
 
     
     
       6. The image reading device of  claim 1 , wherein the image reading unit has a connecting connector to which the one end part of the flat cable is connected,
 the image reading unit has a vertical wall part provided at a side of the flat cable than the connecting connector and having slit-like insertion hole into which the upper sidewall part of the flat cable is inserted, 
 a surface of the vertical wall part, which is opposite to a side of the connecting connector, is inclined to the side of the connecting connector toward the one side from the other side in the main scanning direction, and 
 the angle restriction part is configured by the surface of the opposite side. 
 
     
     
       7. The image reading device of  claim 1 , wherein the image reading unit has a connecting connector to which the one end part of the flat cable is connected and a protruding wall part protruding from a wall part provided with the connecting connector and facing the upper surface of the flat cable,
 an end edge of a protruding side of the protruding wall part is inclined to a side of the connecting connector toward the one side from the other side in the main scanning direction, and 
 the angle restriction part is configured by the protruding wall part. 
 
     
     
       8. The image reading device of  claim 1 , wherein the angle restriction part is configured to reduce the inclination angle of the flat cable as a curvature radius of the curved part of the flat cable is reduced during the reciprocal movement of the image reading unit. 
     
     
       9. The image reading device of  claim 8 , wherein the angle restriction part comprises:
 a rotating part having an insertion hole into which the flat cable is inserted, extending in the sub-scanning direction with respect to the image reading unit, and held around a shaft line so as to be rotatable; 
 a protruding part protruding radially outside from an outer peripheral surface of the rotating part; 
 a restricting rail fixed to the bottom wall part of the housing and extending in the sub-scanning direction; and 
 an inclination edge part formed in the restricting rail and upwardly inclined from the one side toward the other side in the sub-scanning direction, 
 wherein when a position of the image reading unit exists in an area where the curvature radius of the curved part of the flat cable becomes equal to or less than a predetermined radius, as the curvature radius of the curved part is reduced with movement of the image reading unit, the protruding part is upwardly pushed up by the inclination edge part and the rotating part is rotated in a direction in which the inclination angle of the flat cable is reduced.